Maintenance of lawn sod and landscaping plants is relatively recent in comparison with most of man's arboricultural and horticultural endeavors. However, even in modern times, maintenance of lawn sod and landscaping plants is often accomplished manually, requiring large amounts of time and manpower. Within the past few decades, new tools and methods have begun to be developed to mechanize the maintenance of lawn sod and landscaping plants.
Most smaller scale landscaping, such as for a home or business, consists of a grass lawn or sod, shrubs, and trees. Generally, shrubbery beds and sometimes trees, are separated from the grass areas. This separation can be accomplished in many ways. Plastic, wood, or metal edging around the periphery of the shrubbery beds can be used to define the extent of the shrubbery bed. The edging, together with mulching or chemical treatment of the shrubby bed, will stop the grass from encroaching on the shrubbery beds.
A trench between the shrubbery beds and the grass areas can also be used to define the extent of the shrubbery bed. This "bed defining" trench serves to provide a clear separation of the shrubbery beds from the remainder of the landscape. The shrubbery beds can then be covered with mulch, or treated with chemicals, to prevent grass from growing. Ideally, the bed defining trench should have a straight vertical face adjacent the sod or grass area, and a sloping face which extends toward the shrubbery bed. The bed defining trench is then filled in with bed mulch, such as pine bark or pine straw. The mulch then continues up onto the shrubbery bed to form a layer of bed mulch 2-4 inches thick over the soil exhausted from the trench. In this manner, the bed mulch and the grass are at the same level at the vertical face of the trench, and the bed mulch rises up from there along the sloping face of the trench. The sloping layer of bed mulch forms a stable and aesthetically pleasing definition between the shrubbery bed and the grass area.
Presently, a trench can be dug by hand, or by a known trencher. Hand digging is expensive as it is extremely labor intensive. Additionally, the trench resulting from hand digging is less precise than if the trench were to be dug by a mechanized trencher. This is particularly true for a bed defining trench with a sloping face as described above. Known trenchers, such as a high speed rotor trencher or a chaintype trencher, can only dig a trench with two vertical faces. Different rotors are used on known trenchers depending on soil type (clay, sand or rocky), and the width or depth of trench desired. A trench dug by a known trencher has two vertical faces, and is useful for sprinkler systems or for burying of cable or pipe. A vertical trench as dug by a known trencher can be used for bed defining when plastic, wood, or metal edging is installed in the trench. However, this method of bed defining is not preferred as the edging is nicked or cut by operation of a lawn mower or power edger. Additionally, plastic edging will warp vertically and pull up out of the ground.
A known trencher cannot dig a bed defining trench with a sloping face. A bed defining trench with a sloping face can presently be formed by digging a trench with two vertical faces using a known trencher, and then manually digging out the sloping face. Alternatively, a bed defining trench with a sloping face could be formed by manually digging the entire trench.
As will be described in detail below, the present invention overcomes the deficiencies of and problems associated with the conventional technology noted above.